Retracting mechanism for boring tools



p 1942- D. SCOTT ETAL" 2,27

' RETRACTING MECHANISM FOR B-ORING TOOLS Filed April 27, 1939 lIHlll 156 637 Ora:

G7Z6l'dZd I. (521077 George /I. w/za'ifimamy flank J! GZendan @WYhMPatented Apr. 7, 1942 UNITE o s'rer es RETRACTING MECHANISMFOR'BORINGITOOLS j Gherald D. Scott," George'A; Whittemore, and 1 Frank A. Glendon,Worcester, Mass, assignors to The Heald Machine Company, Worcester,Mass, a corporation of Massachusetts Application-April, 1939, Serial No.270,385

14 Claims.

The present invention relates: to boring tools, and particularly to anarrangement for obtaining,.inresponse'to cessation of a boring'toolsrotation,xthe retraction of-the boring tool radially::ofits spindle axisat the endof each boring operationythus' to prevent any scoring of thefinishedworkpiece-bore on. the ensuing: withdrawal of the tooltherefrom;

In the -Schmidt Patent- No. 2,058,359; dated October 20,- 1936, isdisclosed an arrangementwhich'utiliz'es centrifugal force created by aboring-tools rotation-to maintain; during each boring-operation,thedesired radial projection of said tool from its axis of rotation-thetool being, retracted when, by the cessation of its rotation,saidcentrifugal: force is no longer supplied. An object of the presentinvention is to utilize this sameprinciple in a greatly simplifiedarrangement,.involving a minimumrnumber of parts to accomplish thedesired results in a more certain manner.

The above and further objects and advantages of the invention willmorefully appear from the following-detailed description taken in connectionwith the accompanying drawing, in which'- Fig. 1 is a View in sideelevation, partly in section, -ofmechanism in accordance with our' in--vention, and showing the boring tool in working or operative position.

Fig.2. is an end elevation of Fig. l, with parts broken away.

Fig.3 is a sectional View along the line 3-3 of Figlv-2.

Fig. 4 is afragmentary large scale sectional view on the line 44 of Fig.2, showing the parts as theyappear in the retracted or non-workingposition of the boring tool.

Like reference characters refer to like parts in the different figures.

Our invention is readily applicable to any rotary tool spindle, forexample, as shown in Fig l, the spindle 2 which is suitably journalledin a housing or mounting I and which carries onits projectingend a faceplate 3 adapted to have attached thereto, as by bolts 8, 8, a circularhead orshell 1 which, as hereinafter described, supports thetool-carrying and tool-retracting devicesof our invention.

The boring tool'is'shown at '5, the same being held as bya set screw 6,so as toproject 'radi'ally from za spindle extension 4; the latterprojects forwardly from a circular plate II, from whose rear faceprojects a diametrically extending tongue Ill-which fits in andisreceived by a diametrically extending slot 9 of the 'head or shell 'l.The attachment of 'tool-carrying'mein her I l to the shell 1 is by meansof a pivot shaft l2towhich the tongue l0 maybe sec'uredas by means of aset screw l2; this pivot shaft 'I2 is suitably journ'alled' in the shellI onan 'axis substantially at right anglesto the spindle'axisandradiall$ offset therefrom. Thus the tool car rying member I I isconstrained by said tongue and slot-connection' 9 to rota'te 'with the'spindle 2; however, said member II, by reason of its slight spacingshown at! I' ,"from' the-'front' face-'ofshell 1, is capable'of alimitedrocking movement, about-"the axis of saidpivotshaft I2.

On the-"other side of the spindle 'axis from the shaft l 2 and in'parallel relation-to the shaft l2 isfarrange'd'a rod or shaft [3 whichis suitablyjourn'alled' at its end portions; like the-"shaft l2,

in "the cheeksof'shell l, on opposite sidesof the latters slotor recess9. Around the central' or intermediate-portion of shaft l3,'the-tonguex'lll weight 14 which is located ina recess l8 of the' shell'Llbehindthe tongue lw Said-recess lB'is con siderabl-y'wider than therecess-l1, thus to accommodate a-weight' M which is considerably widerthan its carrying lug l5-,'as showninFigB:

On oppositesides 'of the lug-4 5,v as shown in- Fig.=- 3; are eccentricsleeves Ill-secured as+ by pins 2ll--to'the *shaft 13 and turnablyreceived in bores 2 l provided by" portions 'of V the' tongue '10 onopposite sides of the latters recessll; by

virtueot this-arrangement, any slight rocking moVement-ot-the shaft l3will so react-onthetongue I 0 as: to give the plate l l a slight rockingmovement (permitted by the-spacing V I I about the axis of the shaft 12,-thereby providing for a slight movement of thepoint of the boringtool 5 toward or away from lthe axis of rotation of l the spindle zs-The pins 20 are preferably in te'gralwith screws 28 threaded intheweight M for. the passageofsaid pinsil, the adjacent portions of'thetongue I0 provide thelslots'lI, which are slightlyelongated-as-showninFig. 4, to permit the movement of said pins when the shaft i3 isrocked. w

The weight [4, when the spindle-2 is at rest, isin the position of Fig.4, bei'ngheld in this position by, spaced coil springs 22,'Fig..2,-these springs" being backed up bysuita'ble threadedplugs 23, Fig- 4,positionedtin an en'cir'clingpor-i tionof the shell 1." This position"oflthe shell 1 betweenthe plugs 23 provides a set screw 24, Fig.

of the boring tool radially of its axis of rotation to withdraw theboring tool from operative position at the end of each boring operationand this withdrawal movement involves a slight'rocking movement of themember I I' about its axis (the axis of the shaft [2). member ll shiftsthe cutting tool inwardly toward the axis of the spindle 2, the axis onwhich;

the tool is rotated. The mechanism also provides for an outward radialprojection-of the tool into operative position when the spindle isrotated.

.When the spindle is at rest, the weight M, by which {the radialprojection and retraction of the toolisobtained, isheld by the springs22 in the position of Fig. 4, and the tool is in retracted position. Theeccentric sleeves l9 are positioned with the greatest eccentricity ofthe sleeves in a direction away from the axis of the spindle, as bestshown in- Fig. 4, in which the eccentricity is greatly exaggerated.

When the spindle is rotating, the centrifugal force exertedon the weightM causes it to move This movement of the outwardly. against the holdingaction of the springs 22, thereby turning the shaft l3 clockwise,Fig.'4,so that: the. eccentric sleeves act as cams to turn the member H aboutthe axis of the shaft l2 through a very slight angle into the positionshown byFig. 1. This turning movement of the member ll disposes theboring tool into the operative position of Fig. 1, and this operativepositionnis limited by the set screw 24 which determines the outwardswinging of the weight I4 and thus limits the effect of the weight onthe member H.

"When the spindle is stopped, the springs 22 cause the weight 14 to moveinwardly into the position of 4, thereby turning the shaft'l3counterclockwise, with a resultant counterclockwise rocking of member IIon the axis of shaftv l2, to retract the tool 5 slightly from itsoperative position. It will be understood thatthe opposite walls of thebores or slots 2| receiving the eccentric sleeves or cams l9, are spacedapart to correspond. exactly with the diameter of the outer surface ofeach of the sleeves orcams I9, so that any turning movement of the shaft13 will provide a corresponding turning of the mem-' ber ll. With thearrangement of the parts shown, the angular turning movement of themember I I will be extremely small and the effect willbe a very smallinward movement of the boring tool 5 toward its axis of rotation. Aninward movement of one or two thousandths of an inch is suflicient toassure a satisfactory retraction of the tool and the mechanism shownwill obviously provide at least this amount of retracting movement. 1

From the foregoing it will be apparentthat the present inventionprovides very simple structure by which, upon a rotation of the boringspindle, the boring tool will be outwardly projected radially of itsaxis of ,rotation into operative position, this position beingaccurately determined by suitable limiting means, in this case, the setscrew 24. Upon stopping of the spindle 2 the coil springs 22 becomeoperative to move the weight l4v inwardly, thereby turning the eccentricsleeves I9 within the slots or bores 2| for retracting the boring toolfrom its operative position by a slight inward movement of the toolrelative to its axis of rotation. i

We claim:

1. In mechanism of the class described, a rotatably mounted spindlemember, a tool carrying member carried by said spindle member andmounted for rocking movement relative to said spindle member on an axissubstantially at right anglesto the axis of the spindl member, andcentrifugally actuated means carried by one of said members andconnected to the other of said members, said means being moved inresponse to rotation .of the spindle member for procuring a rockingmovement of the carrying member to dispose the tool thereon in boringposition.

2. In mechanism of theclass described, a rotatably mounted spindle, atool carrying member carried by said spindle and mounted for rockingmovement relative to said spindle on an axis sub:

stantially at right angles to the axi of the spindle, centrifugallyactuated means rotatable with said spindle and movable in responseto"rotation of the spindle for procuring a rocking movement of thecarrying member to dispose the tool thereon in boring position, andmeans for limiting the movement of said centrifugally actuated means fordetermining the operative position of said tool.

3. In mechanismof'the class described, a rotatable spindle, a toolcarrying member mounted on said spindle for rotation therewith and forrockingmovement relative thereto about an axis substantially at rightangles to the sp ndl axis,

a pivotally mounted weight having its pivotal axis spaced from thespindle axis and movable by centrifugal force when th spindle isrotated, and connections between said weight and the tool carryingmember for moving the latter into openative position upon rotation ofsaid spindle.

4. In mechanism of the class described, a rotatable spindle, a toolcarrying member mounted carrying member about its axis when said spinedie is rotated, to dispose the tool thereon in boring position, andmeans for limiting the turning movement of the weightfor determining theoperative position of said tool.

5.. In mechanism of the class described, a rotatable spindle, a toolcarrying member con-. nected to said spindle for rotation therewith and,rockable on an axis substantially at right angles to'the axis of thespindle, a pin carried by said spindle and adapted, by turning movement,to procure a movement of the tool carrying member about its axis, a camon said pin and engageable with-the tool carrying member to rock same onits axis by turning of the pin, and centrifugally actuated means movablein response torotation of the spindle forturning said pin.-

6. In mechanism of the class described, a re tatable spindle, a toolcarrying member connected to said spindle for rotation therewith, androckable on an axis substantially at right angles to the axis of thespindle, a pin carried by said spindle and adapted, by turning movement,to procure a movement of the tool carrying member about its axis, a camon said pin and engageable with the tool carrying member to rock same onits axis by turning of the pin, and a Weight connected to said pin andmovable by centrifugal force resulting from the spindle rotation forturning said pin.

7. In mechanism of the class described, a rotatable spindle, a toolcarrying member connected to said spindle for rotation therewith, androckable on an axis substantially at right angles to the axis of thespindle, a pin carried by said spindle and adapted, by turningmovement,to procure a movement of the tool carrying member about its axis, a camon said pin and engageable with the tool carrying member to rock same onits axis by turning of the pin, a weight connected to said pin andmovable by centrifugal force resulting from the spindle rotation forturning said pin, and means for limiting th movement of the weight todetermine the operative position of a tool carried by said member.

8. In a mechanism of the class described, a rotatable spindle, a toolcarrying member connected to said spindle for rotation therewith, and

rockable on an axis substantially at right angles to the axis of thespindle, a pin carried by said spindle adapted, by turning movement, toprocure a movement of the tool carrying member about its axis, a cam onsaid pin and engageable with the tool carrying member to rock same onits axis by turning of the pin, a weight connected to said pin andmovable by centrifugal force resulting from the spindle rotation forturning said pin, thereby rocking said member to dispose a tool thereonin operative position, and resilient means for moving said weight in theopposite direction, thereby to rock said member for a retraction of saidtool when saidspindle comes to rest.

9. In mechanism of the class described, a rotatable spindle, a toolcarrying member connected to said spindle for rotation therewith androckable about an axis substantially at right angles to the axis of thespindle, a pin carried by said spindle and adapted, by turning movement,to procure a movement of the tool carrying member about its axis, a camon said pin and engageable with the tool carrying member to rock same onits axis by turning of the pin, a weight connected to said pin andmovable by centrifugal force resulting from the spindle rotation forturning said pin thereby to so rock said member as to project a toolthereon into operative position, resilient means engageable with theweight for moving said weight in the opposite direction, for rockingsaid member to retract said tool, and means for limiting the movement ofthe weight by centrifugal force to determine the operative position ofsaid tool.

10. In mechanism of the class described, a rotatable spindle, atool-carrying extension pivoted to said spindle on an axis substantiallytransverse to the spindles axis of rotation, a

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tongue-and-slot connection between said parts, to insure their rotationin unison, a, device carried by one of said parts and movedcentrifugally, in response to the spindles rotation, to force saidextension about its pivot to a position which disposes a tool thereon ina predetermined operating position, and means including a spring formoving said extension to a tool-retracting position, upon cessation ofsaid spindles rotation.

11. In mechanism of the class described, a rotatable spindle anextension thereof pivoted thereto on an axis substantially transverse tothe axis of rotation, a boring tool projecting radially from saidextension in axially spaced relation to said pivotal axis, a deviceoperatively associated with said spindle and said extension and movablecentrifugally in response to rotation thereof to force said extensionabout its pivot to a position projecting said tool in an operativeboring position, and means including a spring for moving said extensionto a tool-retracting position, upon cessation of said spindles rotation.

12. In mechanism of the class described, a rotatably mounted head, atool-carrying member pivoted to said head and having a tongue-andslotconnection therewith, the opposing faces of said parts being slightlyspaced to permit limited movement of said member on its pivotal axis, adevice carried by one of said parts and moved centrifugally in responseto their rotation to rock said member about its pivot to a positionwhich projects a tool thereon in a predetermined operating position, andmeans including a spring for moving said member to a tool-retractingposition, upon cessation of said spindles rotation.

13. In mechanism of the class described, a rotatable spindle anextension thereof pivoted thereto on an axis substantially transverse tothe axis of rotation, a boring tool projecting radially from saidextension in axially spaced relation to said pivotal axis, a devicepivoted to one of said parts on an axis on the opposite side of thespindles axis from the pivotal axis of said extension, said device beingmovable centrifugally inresponse to the spindles rotation, to force saidextension about its pivot to a position projecting said tool in anoperative boring position, and

means including a spring for moving said extension to a tool-retractingposition, upon cessation of said spindles rotation.

14. In mechanism of the class described, a, rotatable spindle, anextension thereof connected to rotate in unison therewith, a boring toolprojecting radially from said extension, the latter being pivoted tosaid spindle for rocking movement about an axis substantially at rightangles to the spindle axis, said pivotal axis being in a plane to whichthe projection of said tool is substantially perpendicular, andcentrifugally actuated means movable in response to spindle rotation forrocking said extension about its pivotal axis to dispose said tool inoperative boring position.

GHERALD D. SCOTT. GEORGE A. WHITTEMORE. FRANK A. GLENDON.

